My problem with the Z-drugs is that after taking a reasonable dose, say, 10mg of Ambien (zolpidem), I feel totally normal. So I potentiate it with a beer or two. Usually, no more because I've done some very silly things with the 3 beer (12.oz., 6%) + zolpidem combo.
I've read and heard enough accounts from other people who experience the same sober feeling after taking similar doses. I get energized but feel totally normal and in that state, I could easily have done something foolish enough to end up hurting myself or others. So far my mistakes have involved cooking ludicrous invented recipes and falling asleep while the dish is on the stove/in the oven. Once, I drove on that combination (very, VERY bad me). I was lucky, but I stopped going past the 10mg + 2 beer dosage because I want to avoid jail or hurting someone else. And while I still occasionally go out tagging on the combo. Z-drugs remove my internal criticism mechanism, so I've actually done some great art under their influence. I absolutely will not allow myself to drive though.
Just something to keep in mind. I've done quite a range of drugs but I consider the Z-drugs some of the most potentially dangerous b/c of the reckless "sobriety" effect.
